Heat-regulating system



H. W. SWEATT ET AL HEAT REGULATING SYSTEM Filed Feb. 2, 1924 2 Sheets-Sheet l M/l/N Luv: 6'

v /v YEN TOR6 H/m OLD h 6 115/? TT FREDERICK 6. DE/V/ 6 ON j I firUM @aMlv-fhrwmq fi'TToR/yEra Patented May '29, 1928.

UNITED STATES PATENT OFFICE.

HAROLD W. SWEATT AND FREDERICK S. DENISON, OF MINNEAPOLIS, MINNESOTA, AS-

SIGNORS, BY MESNE ASSIGNMENTS, TO MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF DELAWARE.

HEAT-REGULATING sysrmr.

' Application filed February 2,1924. Serial No. 690,281.

This invention relates to new and useful improvements in heat regulating systems, such as fluid fuel burning apparatus, either liquid or gaseous. It more particularly relates to such apparatus of the motor-actuated type. The form here disclosed is of one adapted specificall for use in conjunction with oil-burning eating plants of the motor-actuated blower type.

The ignition of the oil at the burner may be accomplished by way of a gas pilot which is provided with means operable to assure the proper ignition such as by the expansion of the pilot, as is shown in the prior copending application of one of the joint inventors hereof, Frederick S. Denison, Serial Number 605,736, filed December 8, 1922, or that of the joint inventors hereof, Serial Number 627,699, filed March 26, 1923; or, the ignition may be accomplished by way of a spark plug as disclosed insaid Denisons prior application, Serial Number 603,588, filed November 27, 1922; or by way of a combination of both as is shown in said Denisons application Serial Number 629,057, filed March 31, 1923. Both in the case of the gas-ignition and the spark plug ignition, it is decidedly advantageous, in order to prevent waste, to expand the gas or energize the spark plug for only a predetermined interval. This is conveniently effected by electrically operated means connected with the blower-motor circuit so that the ignition means is operated upon a closure'of the motor circuit and actuation of the motor. The motor circuit isusually provided with a. switch or circuit-closer, either automatic (such as a thermostat) or otherwise. It sometimes occurs that the supply of'electrical energy is interrupted for a temporary period by accident, inadvertence, acts of the elements or in emergencies. More particularly in the case of the automatically controlled circuit-closers, such contingency does not permit a renewal of the ignition because the motor circuit is already closed; hence, there may occur the disadvantage of having fuel directed to the burner where itis unconsumed.

Tn the novel invention forming the sub ject-matter of the present application, additional or auxiliary means are provided in- Y stantaneously to re-operate the ignition means after a temporary interruption of the electrical supply to the closed motor circuit. Such means causes the ignition to perform again its cycle of operations whereby the ignition is operated for the desired interval.

The object therefore of this invention is to provide an improved heat-regulating apparatus.

Other objects of the invention will more fully appear from the following description and the accompanying drawings and W111 be pointed out in the annexed claims.

In the drawings there has been disclosed a structure designed to carry out the objects of the invention but it is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claims which follow. Figure 1 is a wiring diagram of the apparatus with certain electrical devices diagrammatically represented therein.

Figure 2 is a vertical sectional view of the make-and-break device; and

Figure 3 is a detail view of the circuitclosers.

In this selected embodiment of the invention there is disclosed a motor-actuated oilburning apparatus employing a spark plug as the ignition means for the oil at the burner, the functions of the apparatus be ing automatically. controlled by an electrothermostatic means.

The novel general features of such an indicated installation form the subject-matter of a prior co-pending application of one of the joint inventors hereof (Frederick S. Denison) Serial Number 580,360, filed August 7, 1922; while the use of aspark plug is shown in a prior co-pending application of the other of the joint inventors hereof (Harold W. Sweatt) Serial Number 580,344, filed August 7. 1922. In the last-mentioned application, the spark plug is constantly energized during the operation of the usual blower-motor; while the herein illustrated use of a spark plug which is energizable only for a predetermined interval is disclosed in the previously mentioned application Serial Number 603,588.

In order to point out clearly and specifically the novel features of the present invention, it will be necessary to describe and explain in more or less detail the associated parts of the apparatus.

The ignition means here shown consists of a common form of spark plug 5 energizable to provide a hot spark for ignition of fuel furnished to the conventionally represented burner 6 having the base of itsp-an apertured to permit the insertion of the end of the relatively large blower pipe 7. A fuel supply pipe 8 is concentrically disposed within the pipe 7 adjacent its end. Air is upwardly discharged around the end of the fuel supply pipe to the pan and against the usual overhead target 9. The air is forced through the pipe 7 by a blower 11 driveii by a prime mover such as the electric motor 13. The motor is provided with leads 12 and 14. The lead 12 is directly connected to the side 15 of the main feed or supply line while the lead 14 is indirectly ponnected to the other side 16 of the main me. a

The vaporization of the liquid fuel supplied from a suitable source through the pipe 8 to the burner is well-known in this art. The spark plug 5 is adapted to receive electrical energy from the usual spark coil 17. This coil 17 has a connector 18 leading to the wire 19 of the low side of the transformer 21. The other connector 22 of the coil 17 leads to a make-and-break device interposed between it and the connector 23 leading to the other wire 24 of the low side of the transformer 21. The high side of the 1 transformer has connectors 25 and 26, the

' former leading to the side 16 of the main line while the latter is in electrical connecttion through the lead 12 of the motor with tion of its solenoid and, after de-ene rgizadamped.

tion of the solenoid, to descend at a retarded or dampedpace so that its return occupies a predetermined interval during which the spark coil circuit may be closed and the spark plug energized. Such a device is shown and described in detail in a prior copending application of the inventorshereof, Serial Number 627,699, filed March 26, 1923, and in the prior co-pending applications of one of the joint inventors hereof, Frederick S. Denison; Serial Number 603,588, filed November 27, 1922; Serial Number 605,736 filed December 8, 1922; Serial Number 629,057 filed March, 31, 1923. This device includes a fluid chamber casing 27 within which the plunger 28 is adapted to reciprocate, the lower end of the plunger being valved to permit the ready ascent of the plunger end through the fluid chamber and to cause the fluid to be shunted through a constrlcted passage 30 upon descent of the plunger whereby, upon de-energization of the liftin solenoid 29, the descent is he solenoid surrounds a" large portion of the casing 27 and is provided with a connector 31 running to the lead 12 of the motor and with a connector 32 running to the elongated blade 33 of a circuitbreaker, the other similar spacedblade 34 of which is joined by the connector 35 to the other lead 14 of the motor. An electric circuit may be established across these spaced blades by the metallic electrically conducting head 36 of the plunger 37 reciprocable in the solenoid 38. This contactestablishing head 36 is adapted to be normally upwardly held in circuit-closing posi tion by the coiled tension spring 39. Upon energization of the solenoid 38, the head is downwardly pulled and held against the tension of its spring so that the circuit is broken across the blades 33-34. This solenoid is adapted to be energized by means of a current sent through its two connectors 41 and 42, the connector 41 leading to the thermo-bar 43 and the connector 42 leading to the supplemental contact blade 40. Before describing the energization of this solenoid 38 by the thermostat from the low side of the transformer 21, the wiring and structure of the associated parts of the apparatus will be first described.

Broadly, this wiring diagram discloses a fluid fuel burner installation of the type employing a. motor adapted to drive a blower to deliver air under pressure to the burner in order to vaporize the fuel. The

control of the blower-motor and the spark plug solenoid 29 and the circuit-breaker solenoid 38 are so inter-related that, when the motor circuit is closed, both solenoid cirplunger 37 of the solenoid 38 is downwardly pulled and retained. The elongation of the blades 3334 provides suflicient time interval to assure thecomplete energization of the spark plug solenoid 29 with the consequent raising of the plunger 28. When the plunger 28 is raised, the terminal detent 44 releases the spring metal conductor.45 so that it may assume normal position in electrical engagement with the contact 46 of the connector 23. This conductor 45 has the connector-'22 of the spark coil 17 connected thereto. I i

The thermostatic control of the motor may first be explained, thereafter the control of the spark-plug solenoid circuit and the control and function of the circuit-breaker provided by the solenoid 38.

Generally considered, here is provided a switch having a pair of spaced terminals and a circuit-closer co-operable therewith to cuits are closed and the plunger28 of the solenoid 29 1s upwardly pulled while the energize these two solenoids or coils so that.

the armature may be moved in a direction to effect the desired opening or closing of the switch. The means here shown for singly energizing the coils is a thermostatic device.

The lead 12 of the motor 13 is directly connected to the side 15 of the main line circuit while the lead 14 of the motor is con nected to the other side 16 of the main line through the circuit-closer 47 and its spaced blades 48 and 49. The circuit-closer 47 is shown in the drawings in closed position butis adapted to be upwardly rocked to open the motor circuit from the main line.

A convenient mode of rocking this circuitclos er both out of and into circuit-closing POSIlIlOIl' is provided by means of the rockshaft 51 which carries the circuit-closer 47. This rock-shaft is adapted to be rocked by an armature 52 reciprocably mounted within the core of two solenoids which are adapted singly to be energized to produce opposite polarity so that the armature may be selectively moved in opposite directions. The twosolenoids may conveniently be provided by a single coil having an intermediate tap so that current may be oppositely directed through each half to give the desired opposite polarity to the individual units. For convenience of reference they 7 may be designated as the upper or circuitclosing coil 53 and the lower or circuit-opening coil 54.

The selective energization of these two coils is effected, in this apparatus, by means of a thermostat. Each coil'is provided with a circuit leading to a suitable source of electric energy and each such coil circuit is adapted to be electromagnetically closed or opened by the thermostat and the parts are so arranged that the upper or circuit-closing coil is energized by the so-called cold side of athermostat circuit while the lower or circuit opening coil is energized by the hot side of the thermostatic circuit.

Each coil is provided with a circuit connected to the main line. The lower coil 54 has a wire 55 leading from the bottom of its winding to the motor lead 12 constantly in electrical connection with the side 15 of the main line or supply circuit. The tap 56. which functions as the top of the lower coil, is connected to the wire 57 leading to the left, as shown in the-drawings, to a movable armature-contact 58 normaly held upwardly out of engagement with its complementary contact 59 by any suitable means such as the tension spring 61. The relativelv fixed contact 59 is connected by the wire 62 to the contact blade 63 insulated from a complementary blade 64 having a wire 65 leading to the connector 25 of the other side 16 of the mainline. An electro-magnet 66 is positioned beneath the armature-contact 58 and is adapted, upon energization by the hot side of the thermostat (as will be hereinafter described) to close the relatively high voltage circuit through the opening coil 54 and thus to move the rock-shaft 51 and open the motor circuit across the spaced blades 48. Thus, the lower coil 54 is provided with its circuit which may not only be opened and closed by means of an armature at one point but also may be opened and closed at another point across the blades 63 and 64. The closure of the latter break is effected by means of a circuit-closer 67 carried by the rock-shaft 51 and operable thereby. This circuit-closer is thus co-operable with the circuit-closer 47 of the motor circuit.

The upper coil 53 has a wire 68 leading from the top of its winding to the knife blade 69 electrically insulated from its complementary blade 71 connected by the wire 72 to the connector 25 of the side 16 of the main line. The break across the blades 69 and 71 is adapted to be closed by the circuit-clo'scr 73 carried, similarly to the circut-closers 47 and 67, by the rock-shaft 51. This circuit-closer 73 is diagrammatically here shown in dotted lines in order to indicate that it is not in circuit-closing position because the circuit-closer 67 is so shown, it being understood that these circuit-closers 67.and.73 are opposite in function; that is, when the circuit-closer 67 is in closing posi tion, the circuit-closer 73 is in circuit-opening pos tion and vice versa.

Thev other side of this upper coil circuit is through the tap 56 to the wire 57 and thence, to the right as shown in the drawing, to the movable armature-contact 74 which is yieldablv held upwardly by the tension spring 75 out of electrical engagement with its complementary fixed contact 76 connected by the wire 77 to the motor lead 12 running to the side 15 of the main line. An electromagnet 78 is positioned below the armature contact 74 in order, upon energization. to draw the contact 74 into engagement with the fixed contact 76 and thus to close the coil circuit across this break. The electromagnet 78 is adapted to be energized by the cold side of the thermostat in order indirectly to start the motor, and, it may be noted in passing that the spark-- plug-solenoid circuit, through the connectors 31-3235 and closed blades 3334, is closed when the motor circuit is energized.

Referring now to the thermostatic control of the motor: The electromagnets 66 and 78 are adapted to be selectively energized by means of circuits established by a thermostat. These circuits preferably derive their electric energy from the motor circuit through the transformer 21. In the drawing. the relatively, high voltage paths are indicated by heavy lines while the relative ly lower voltage paths are indicated by light lines.

' mostat is usually termed the hot side because it is engaged by the heated thermo-bar when the thermostat is above the predetermined temperature resulting in a shuttingoif of the heat. This hot contact has a Wire 81 leading to the bottom of the winding of the electromagnet 66 in order that it may be energized to close the armature 58 across the opened circuit of the opening coil 54. The upper end of the winding of the electro- ,magnet 66 has a wire 82'leading to the knife blade 83. The knife blade 84 is spaced and insulated from its complementary blade 83 and from the supplementary blade 40 (see Figure 3) and this space is occupied by the circuit-closer 85 during the time when the motor circuit is closed. This circuit-closer 85 is mounted upon and is operable by the rock-shaft 51 simultaneously with the circuit-closers 47 and 67. The remainder of the circuit through the electromagnet 66 beyond the blades 8384 is by the wire 86 leading from the blade 84 to the blade 87 and thence by the wire 88 to the Wire 19 of the low side of the transformer.

The cold side contact 89 of the thermostat is connected by the wire 91 to the bottom of the winding of the other electromagnet 78 andthcnce, by the wire 92 from the top of the winding, to the blade 93 which iscomplementary to, and is insulated from, the spaced knife blade 87. The break across these blades 87 and 93 is adapted to be closed by the circuit-closer 94 which is similar in construction, mounting and operation to the circuit-closer 73. Similarly, the circuit-closer 94 is shown in dotted lines in the diagram because the parts are shown in the positions assumed when the motor is running which necessitates the closure of the three circuitclosers 85, 47 and 67. When the motor is stopped, the rock-shaft is turned so that the breaks across the blades 6971 and across the blades 8793 are closed. Hence, the current path from the electromagnet 78 through the wire 92 and blade 93 continues- 19 of the transformer. Such current flow en-' ergizes the electromagnet 66 and downwardly draws the armature-contact 58 against the tension of its spring 61, thus closing a high voltage circuit through the lower or opening coil 54. Such circuit is as follows: side 15 of the main line, motor lead 12, wire 55, coil 54, tap 56, wire 57, the closed armature-contact 58, fixed contact 59, wire 62, blade 63, circuit-closer 67, blade 64, wire 65, the connector 25 to the other side 16 of the main line. The opening coil 54 is thus energized and the armature 52 is pulled, the shaft 51 rocked and the circuit-closer 47 is moved to open position so that the motor circuit is broken and the motor and blower are stopped. As the rock-shaft 51 moves the circuit-closer 47 to open position, it likewise moves the circuit-closers 85 and 67 so that the electromagnet 66 is deenergized by the. break across the blades 83-84 and the opening coil is de-energized by the break across the. blades 6364 and the armature-contact 58. Likewise, by the rocking of the shaft 51, the circuit-closers 94 and 73 are moved to their circuit-closing dotted line positions ready for a call for heat by the cooling thermo-bar.

When the thermo-bar 43 has cooled to the predetermined degree, it is thereby bent to effect electrical engagement with the cold side contact 89. A circuit is then closed ture 74 to closing position) wire 92, blade 93,

circuit-closer 94, blade 87, wire 88 to the other wire 19 of the transformer 21. The electromagnet 78 having moved its armature contact 74 to closing position against the tension of the spring 75 provides a closed circuit for the upper or closing coil 53, as follows: side 15 of the main line, motor lead 12, wire 77, contact 76, armature-contact 74, wire 57, tap 56, upper coil 53, wire 68, blade 69, circuit-closer 73, blade 71, wire 72, connector 25 to the other side 16 of the main line 16. Energization of this coil 53 rocks the shaft .51 to swing the circuit-closer between the blades 48 and 49 so that the motor circuit is established through its two leads 12 and 14. The blower-motor functionsstart and the air discharge draws the fuel from the open end of the pipe 8 and delivers the mixed fuel adjacent the sparkplug 5. As the current flows through the motor leads 12 and 14, it also flows through the shunt circuit to the spark plug solenoid 29 because the break across the blade 33--34 is normally closed by the' head 36 which is tensionally held in suclrposition by the spring 39. Energization of the solenoid 29 upwardly thrusts the plunger 28 so that its detent 44 releases the spring contact 45 to effect electrical engagement with the contact 46. Hence, current flows from the wire 24 of the secondary winding of the transformer 21 to the contact 46, contact 45, wire 22 to the spark coil 17 and thence by wire 18 to the wire 19 of the transformer. The spark coil being energized, the spark plug 5 correspondingly functions to ignite the vaporized fuel.

However, the energization of the sparkplug solenoid 29 is only temporary because the solenoid 38 is energized when the thermo-bar engages the cold contact 89. This solenoid energi'zation is effected by the following circuit from the secondary side of the transformer: wire 19, wire 88, blade 87, wire 86, blade 84, circuit-closer 85, blade 83, wire 42, solenoid 38, wire 41, to the other wire 24 of the secondary winding of the transformer 21. The plunger 37 is thus downwardly drawn against the tension of the spring 39, between the elongated blades 33 and 34 to the position shown in the wiring diagram whereby the spark plug solenoid circuit is broken.

The gravitational or other tensioned descent of the plunger 28 then takes place so that after a predetermined interval the detent 44 depresses the end of the springcontact 45 so that the spark coil circuit is broken. Thus, when the parts are in the position shown in the wiring diagram, the motor is running and heat being supplied by the combustion of the fuel at the burner 6.

It sometimes happens that there is a temporary interruption of the motor circuit,

' such for example as the more or less common occurrence when the power 1s temporarily off If such a contingency occurs the main line. when the motor circuit is in closed position, the motor will be stopped and the burner will go out so that when the power comes on again, the spark plug would not re-function to ignite the renewed supply of fuel. In this novel apparatus, just as soon as the power is taken off, the solenoid 38 is de-energized with the result that the head 36 is raised by its spring 39 to close the break across the blades 33 and 34 of the spark plug solenoid circuit. Therefore, when the current comes on again, the solenoid 29 is again energized, so that ignition of the renewed supply of fuel is assured. Thus, the disadvantage of the accidental interruption of the motor circuit when it is in closed position as well as such interruptions as fuse replacement, accidental opening and closing of the control switches, and temporary cessation of the supply of electric energy from the main line are obviated.

Having thus described our invention what we claim as new and desire to secure by Letters-Patent, is:

1. In an apparatus for burning fluid-fuel; a motor included in an electric circuit, an ignition circuit including a fuel ignition device, two solenoid switches, one in the ignition circuit, and the other in a shunt circuit of the motor circuit, the solenoid of the ignition circuit being energizable by current delivered through the shunt circuit of the motor circuit to move the switch of the ignition circuit to circuit closing position, the solenoid of the shunt circuit under energization operating its switch to open the circuit for deenergizing the solenoid of the ignition circuit, means in the ignition circuit for effecting a predetermined time-period movement of the ignition circuit switch for opening said circuit, and means for restoring the switch of the shunt circuit to normal closing position upon deenergizing the solenoid of the shunt circuit switch from a break in the motor circuit, for supply of current through the shunt circuit to the solenoid of the ignition switch upon restoration of the motor circuit current.

2. In an apparatus for burning fluid-fuel; a motor included in an electric circuit, an ignition circuit including a fuel ignition device, two solenoid sWitches, one in the ignition circuit and the other in a shunt circuit of the motor circuit,the solenoid of the ignition circuit being energizable by current from the motor circuit through the shunt circuit to move the switch of the ignition circuit to circuit closing position, the solenoid of the shunt circuit'under energization operating its switch to open the shunt circuit to deenergize the solenoid of the ignition circuit, and movable into circuit closing position upon a break in the motor circuit to supply current to the solenoid of the ignition circuit upon restoration of the motor circuit current, and after closing the ignition circuit switch operable to open the shunt circuit, and means in the ignition circuit for effecting a predetermined time period controlled opening of the ignition circuit.

In witness whereof we have hereunto set.

our hands this 15th day of August 1923.

HAROLD W. SVVEATT. FREDERICK S. DENISON. 

